Field of the Invention
The present invention relates generally to an arrangement in doors and more specifically to doors constructed to avoid the risks of injuries caused by squeezing or crushing.
In door arrangements of this kind it is common practice to arrange for instance guide tracks extending vertically on either side of an opening in a building wall. The guide tracks extend adjacent or above the opening, via a curved portion, preferably horizontally further into the building. When the door traverses the curved portion a gap forms between neighouring door panels as the latter are being rotated relatively to one another. The gaps are a potential crushing injury hazard. It is already known to use various devices to lessen such hazards.
EP Patent 0 326 131 discloses one example of a anti-squeezing-injury joint comprising several hinges disposed along a pivot axis positioned in the vicinity of a lateral face of two neighboring door panels. Neighboring door panels have one convex and one concave member which are in contact with one another only when the door panels extend in parallel. As the panels are being rotated relatively to one another, a narrow gap forms between them. In order to avoid squeezing-injury hazards in the area of the hinges upon mutual rotation of the door panels, specially designed guards are positioned adjacent the hinges.
Disadvantages common to all devices of the type outlined above is that the convex/concave members are not made use of as supporting faces when the neighbouring door panels are being rotated relatively to one another. As a result, the hinges must absorb all stress exerted during the turning movement, and consequently a number of hinges must be positioned along the pivot axis in order to produce a safe and durable door. In turn, this arrangement leads to more expensive doors comprising an increased number of parts. Doors of this kind are also difficult and time-consuming to mount because of the number of hinges. Because the hinges are located on the inner face of the door panels doors of this kind also require that a particular crushing-injury guard is positioned in the area of the hinge, which further affects the costs and the complex nature of the product negatively. In addition, dirt and moisture could collect in the minor gaps formed when adjacent door panels are being rotated relatively to one another.
In the Danish Patent Application No 0436 93 is disclosed another crushing injury guard hinge according to which adjacent door panels are formed with one convex and one concave member. In this case, the pivot axis is located between the lateral faces of the door panels. The convex and concave members are in engagement during the entire rotational movement, thus forming a bearing face on which the hinge may be supported. In this case, pivot pins are provided at the ends or neighboring door panels, locking them to one another. In addition, the hinge is provided with guide means on the inner face of the door panels, along the hinge. The guides are adapted to stiffen the construction so as to prevent the neighbouring door panels from being displaced relatively to one another in an area spaced from the hinges.
A problem found with this construction is that the guides make the construction more expensive and in addition difficult and time-consuming to mount. Furthermore, the guides occupy space on the inner face of the door and since they project beyond the lateral face of the door on the inner face thereof they are sensitive to impacts. In addition, they are configured with sharp and pointed edges which may be the cause of injuries.
A low-friction slide rail is provided at least on one of the members. In accordance with the drawings, the slide rail is positioned on the concave member. Wear-induced damages, such as scratches, discolorings and the like, may form on the convex member after some time of use. Since this member is not exchangeable the entire door panel must be replaced if one wants to prevent the wear damages from being visible when the door panels are being rotated relatively to one another.
Furthermore, at least one of the members is formed with a resilient sealing strip. The provision of separate slide rails and sealing strips involves the use of several parts, which in turn means that an increased number of pieces need to be kept in store and that a larger amount of components need to be handled when the door is being manufactured. In addition, the number of attachment points to secure the rails and the strips is increased.
In this prior-art device the rollers are arranged on the inner face of the door, spaced from the pivot axis. In an arrangement of this nature the guide tracks normally extend at an angle to the lower part of the opening in which they are attached. In this manner, the rollers force the door towards the opening in the lower position of the door, providing a sealing effect. An, arrangement of this kind requires numerous parts, increases the stress on the door panels in the area of the hinges, is difficult to mount and increases the maintenance and repairs, all of which in combination leads to an expensive door construction.
The Swedish Patent Specification No 8901857-6 discloses another example of a crushing-injury preventing hinge. Also in this case, neighboring panels are formed with one convex and one concave member which are snap-fitted one into the other. The pivot axis of this device is positioned between the lateral walls of the door panels and the concave and the convex members of adjacent door panels engage during the entire rotational movement and thus are used as bearing faces. In this case, the door panels are manufactured entirely from injection-moulded plastics, a method necessitating large and expensive molds and producing panels having a rigidity that make them particularly suitable for closure of comparatively small-size openings. On account of the snap fit between the convex and the concave members a high degree of manufacturing accuracy is required and it also involves risks that the concave member will crack when being snapped onto the convex member. The door panels are manufactured as one single piece, with the result that the wear faces between the convex and the concave members are not replaceable separately. Furthermore, no sealing strip is arranged on the outer face of contacting door panels along the hinge. As a result, moisture and dirt may enter into the hinge, particularly when the external face of the door is exposed to heavy wind loads.